Method and means for photographing areas of limited accessibility



Feb. 26, 1963 c. K. STARKS ETAL 3, 7

METHOD AND MEANS FOR PHOTQGRAPHING AREAS 0F LIMITED ACCESSIBILITY FiledApril 3, 1958 s Sheets-Sheet 1 WITNESSES INVENTORS Cecil K. Starks and(fig-Md R. G 23 Norman L.Corr oll.

AT RNEY Feb. 26, 1963 c. K. STARKS EI'AL 3,079,502

METHOD AND MEANS FOR PHOTOGRAPHING AREAS OF LIMITED ACCESSIBILITY 3Sheets-Sheet 2 Filed April 3, 1958 Feb. 26, 1963 c. K. STARKS EIALMETHOD AND MEANS FOR PHOTOGRAPHING AREAS OF LIMITED ACCESSIBILITY FiledApril 5, 1958 3 Sheets-Sheet 3 Flg 6 United States Patent Ofifice 3,079sea METHGDAND 'MEANS lFGR PHG'EQGRAPHENG AREAS 'OF LHMH'IED ACCESSEBIHTYCecil K. 'Starltsffaahmontyand Norman L. tlarroll, Richlan d'To'wnship,Allegheny =-County, Pa, assignors to Westinghouse Electric Corporation,llast Pittsburgh, Pa e corporation of Pennsylvania Filed'A-pr. 3, 1958,fier. No; 726,129 15 Claims.- ((13. 25@65) The present invention relatesto photographic film'and light-source arrangements for photographing'theinterior surfaces of narrow or otherwise confined passages, enclosuresand the like, and more particularly to method and means'for-making-photographs for purposes of inspecting or testing theaforementioned interior surfaces;

Heretoforeit has been 'the practice to use a so-called panoramic camerafor photographing the aforementioned t interior su'rfaces. Thispriordevice not only is complicatedand expensive, but requires a highintensity light source, mirror, scanning mechanism, various-lightdirecting'adapt'erjs, and optical components, depending upon theapplications in which the camera is employed, in addition to the usualcameramechanism.

Inthe manufacture of various types of reactionvessels, heatexchangersand tubular elements such as heat exchanger tubing, pipes, gunand rifle bores, it is desirable to inspect the internal surfacesthereof for the purposes of ascertaining the presence of any defectswhich may result'from c-asting,'drawing or other manufacturing process.;In still other applications, it is necessary that such items besubstantially'free from corrosionor other in terior surface defectsbefore placing the tubular element, vessel or'the like into use. Oneconvenient arrangement for sotesting the interior surfaces'of such itemsof equipment or components thereof is to photograph directly theseinterior surfaces and to determine fromthe r sultant photograph thepresence of corrosionor other surface defeet as expressed in terms ofrelative exposure of the photographic film.

In accordance with the invention, a method and means are-disclosed forconveniently'exposing a photographic film placed adjacent these interiorsurfaces by the reflection of light therefrom. If, of course, theaforesaid interiorsurfaces are relatively freefrom surface defects, thereflected light will be substantially uniform and the,comparative-absence; of variations in the expose film will indicate that'the interior or other surface being tested or inspected is free ofsurface defects. On the other hand, the presence of corrosion, erosion,cracks, blow holes or -the like at such surfaces will reduce orotherwise changethe amount of light reflected, thereby causing thephotographic filmto b'e variably exposed and thereby toindicatethe'presenceof one'or more of the aforementionedsurface defects.As will be explained hereinafte' morefully,'theinvention is equallyapplicable to any flat orcurved'su'rface, and particularly adapted foruse with those "surfaces of limited accessibility.

In view of the foregoingfan object of the invention is the'provision ofa novel and efficient method for photo graphing interior surfaces,particularly those of limited accesSibiIityL' Another object of theinvention is the provision of a novel and efficient means adapted forphotographing the aforementioned "interior areas.

Further'objectsof the invention are the provision of a means andmethodfor photographing relatively large surface areas of either flat ornon-planar contour.

Stillfotherobje'cts of the invention are the provision ofndVeYcombihat'iohs of a photographicfihn and light sotrrbestherefor"arranged particularly for photographing 3,079,502 PatentedFeb. 26, 15 83 interior surfaces or other surfaces of limitedaccessibility.

A still further object of the invention is the provision of a novel andeflicient light source adapted for use with FIGURE 1 is anisometric'view of a tubularelement and a'photographic means insertedtherein for photographing'an' interior surface thereof in'accordancewith the invention with parts of the tubular element and photographingmeans being broken away for purposes of clar- FIG. 2 is 'apartialisometric view of another form of the'lightsource employed in FIG. 1 ofthe drawings;

H6. 3 is a partial isometric view of still another form of the lightsource employed in FIG. 1;

FIG.4 is an isometric view of another form of the photographing'meansillustrated in FIG. 1 and arranged in accordance with the invention;

FIG. 5 is an isometric view of still another form of,

photographic means" arranged in accordance with the invention;

FIG. 6 is an isometricview of yet another form of the photographicmeansarranged in accordance with the teachings of this invention;

FIG. 7 is a partial isometric'view of the bore of a gun or ride or thelike and a photographic means arranged in accordance with the inventionfor photographing an interior surface of arcuate or other non-planarconfigure-"- tion; and

FIG. 8 is a partial isometric view of another form of the photographicmeans illustrated in FIG. 7.

In utilizing the terms, tubular element, cylindrical olement'and thelike, such terms are used in their broad geometric sense, in which thereis signified not only a circularly tubular or cylindrical element, butany surface formed by a line moving parallel to itself over a planecurve. In accordance with the specific aspects of this invention, thetubular or cylindrical elements herein are of both circular andrectangular cross section.

Referring now to FIGS. 1 and 2 of the drawings, the Iv illustrativeforms of the invention shown therein are adapted for photographing aninterior surface area 20 of a generally cylindrical or tubular element22. In this I arrangement of the invention the surface 20 being photojgraphed is a Wall "of a' substantially rectangular cavity24 formedwithin the tubular member 22. The tubular" member 232 for the purposesof this invention isany form 1 of tubular conduit, for example a flattypeheat exchanger tube or any member having a relatively narrow cavityextending therethroug'n. In accordance'with theinven tion, aphotographic means denoted generally by the reference character 26 isinserted within the narrow cavity '24 and is arranged to photographsubstantially the entire area of the surface 24) by means of lightreflected therefrom onto a conventional photographic film or emulsion.

In furtherance of this purpose, the photographic means 26 comprises alight-transmitting arrangement 28 and a photographicfilm 3b. In thisarrangement of the inven' tion the photographic sheet Si) is generallyrectangular and desirably'is coextensive with the surface area 2% whichis being photographed for inspectional or testing purposes." Forpurposes hereinafter to be described, the photographic film 33 in thisarrangement includes a layer 32 of a conventional, photographic emulsionwhich is deposited upon a clear base, forexample, a substantiallytransparent plastic sheet 34,, serving as a support for the photographicemulsion. The photographic film'3tl is inserted into the cavity 24 to aposition adjacent to, and desirably in contact with, the surface 2t?being photographed.

The photographic means 26 also includes a light-transmitting arrangement2% which likewise is insertable into the cavity 24 of the'member 22. Thelight-transmitting arrangement 28 substantially is coextensive with thephotographic film 30 and in this arrangement includes a sheet 36 of alight-conducting plastic such as methacrylic resin known as Lucite orPlexiglas. By means presently to be described, the light-conductivesheet 36 is arranged to conduct light from a source 33 to the entirereverse surface of the photographic film Stl. The light thus applied tothe photographic film 3% passes through the clear plastic supportingsheet or backing 34 of the emulsion 32 and through the emulsion 32 tothe surface 2d, where it is reflected back onto the photographicemulsion 32. The supporting sheet 3 3 is therefore fabricated from aclear plastic material such as the aforementioned Lucite in order thatthe light can pass therethrough. Furthermore, the backing sheet 34-,being rather thin, is sufficiently flexible to permit conformance of thephotographic film 3% to the surface 2ft being photographed. Thephotographic emulsion 32 likewise is relatively transparent, as is wellknown, to permit passage of light from the light-conductive sheet 36therethrough.

Thus, the light from the light-transmitting arrangement 28 is passeduniformly through the photographic film 3d onto the surface 2%} beingphotographed. However, should any imperfections exist at any area of thesurface 24} in contact with the photographic film 3d, the amount oflight reflected from that area back onto the photographic emulsion 32will be diminished accordingly. With this arrangement, then, thephotographic film 30 is doubly exposed as it were: First a uniformexposure to light passing directly through the film 3h from thelight-transmitting arrangement 23 and second, a probably variableexposure of light reflected from the surface being photographed backinto the film emulsion 32. Since the first exposure is uniform, asaforesaid, the total exposure of the film 39 will reveal any defects inthe surface 24) as under or lesser exposed in the film 3t as determinedby the nature of the defect causing the reduction in light reflection atthe surface Ztl. Thus, it is possible from the pattern of the resultingexposure of the film to determine the existence and location of anyundesirable surface defects and their approximate character, that is tosay, whether these defects are surface corrosion, cracks, erosion, blowholes or the like.

The light supplied to the back side of the film 30 by thelight-transmitting arrangement 28 is obtained as aforesaid from thelight source 33. In this arrangement the light source 23 can be afluorescent lamp having an elongated tubular bulb 4t extending along theoutside edge 32 V of the light-conductive sheet 36. Alternatively, thelight source 38 can be a linear filament type lamp having substantiallythe same configuration. The light source 33 is provided with terminals(not shown) at its ends which are inserted into electrical sockets 44and 36 in a wellknown manner. An electric potential is applied theretothrough suitable conductors denoted generally by the reference character48. The electric sockets 4d and 46 are mounted respectively on theconfronting surfaces of a pair of brackets 50 and 52. The brackets 5dand 52 are rigidly clamped to the light-conductive sheet 36 adjacent therespective outside corners 54 and 56 of the plastic sheet 36. The lightsource 38 thus is positioned a predeterminable distance from the outsideedge 42 of the lightconductive sheet and therefore, the light suppliedfrom the source 38 to the sheet 36 will be of the same intensity as longas the ligt source 38 remains unchanged.

Ordinarily, the light supplied to the outer edge 42 of thelight-conductive sheet 36 will be conducted substantially in coplanardirections therethrough, and most of the light would be radiated fromthe opposite edge 58 and the lateral edges 6th of the light-conductivesheet.

To prevent loss of light and spurious reflections occasioned thereby,the edges 53 and 6t desirably are coated with a light-reflectingmaterial such as a metallic foil.

In the modification shown in P16. 1 of the drawings, the light suppliedto the plastic sheet 36 by the source 38 is withdrawn from a portion ofthe plastic sheet facing the back side of the photographic film 3t anddisposed adjacent the lower edge of the sheet. This portion which istermed a window 62 is formed by etching or peening or by any otherconvenient abrasional process, to impart a rough surface to the window62. The indentations made into surface 64 of the sheet 36, as .a resultof the aforementioned abrasional processes, intercept a portion of thelight transmitted through the sheet 36 and by diffusion and refractionbends a portion of the light thus intercepted to a direction at an angleto the surface 64 of the light-conductive sheet and to the reversesurface of the film 33.

It is contemplated that the entire adjacent surface 64 of the lightconductive sheet, which is coextensive with the photo-graphic film 30,can be arranged as described previously into a light-diffusion windowand that the film 350 can be exposed as described above simply byturning on the light source 38 after the film 30 and thelight-conductive sheet 36 are positioned as shown in FIG. 1. Althoughthis arrangement will work satisfactorily in many applications, thoseareas of the film 30 which are closer to the outer edge 42 and thelight'source 38 will receive progressively greater amounts of light andtherefore a uniform first exposure of the film Elli will not beachieved.

Accordingly, in one arrangement of the invention, the

after the latter is positioned within the cavity 24. In 7 oneapplication where the member having the cavity 24- is disposed in asubstantially horizontal position, the plastic sheet 36 is rested upon alower surface 66 of the cavity (FIG. 2) while the film 3d is placedagainst the upper surface 20. Means are then provided for movingthe'light conductive sheet 36 at a controlled rate longitudinally of thefilm 3t to cause the window 62 to scan the entire reverse surface of thefilm 3%, whereby light emitted from the window 62 thereof is applieduniformly along the length and width of the film 3i).

One arrangement for so moving the sheet 36'includes a pair of screwdrive members 68 and 74 which are threaded into tapped apertures of thelight source mounting brackets 56 and 52, respectively. The screwmembers 68 and 7h are mounted for rotation about their longitudinalaxes, respectively, in a well known manner, and the application oftorque to the drive members 68 and 70 causes longitudinal displacementof the light conductive sheet 36 by engagement of its brackets with thescrew members 68 and 79, as indicated by arrows '72. By so moving thelight-conductive sheet 36, it will be seen that the same amount of lightis applied to those areas adjacent the outside edge i l of the film 3t)as is applied to those areas adjacent the inside edge '76 there- 7 of.This follows from the fact that the source 38 is moved with the window62 and that the light transmitted from the source 38 to the back sideof'the film 3'19 through the Window 62 follows a light-conductive. pathof substantially constant length.

Referring now more particularly to FIG. 2 of the drawings, thearrangement disclosed and described heretofore in connection with FIG. 1is modified in that the light diffusing window 62 is omitted and lightpassing through the light-conductive sheet 36 is refracted at theinward'edge thereof by means of a beveled edge portion 78. The lightthus refracted from the lower edge 78 (FIGI'Z) need not passperpendicularly through the film 3t) as long as at least a portion ofthe light rays are bent toward the back side of the film 3d, and thelimits of travel of the light-conductive sheet are selectedaccordinglyso that'the entire surface of the photographic emulsion 32 isscanned or traversed by the light refracted from the beveled edgeportion 78.

Alternatively as shown in FIG. 3, the retracting beveled edge portion'78 of FIG. 2 can be replaced by a mirrored edge portion 79 likewiseformed at that end of the sheet 36"Whichis opposite from the lightsource 3%. In the latter arrangement, rowever, the edge 79 is beveled inthe opposite relative direction and is disposed desirably at'a 45angle-such that the light being conducted longitudinally through thesheet member 36 will be reflected substantially perpendicularly theretoand'will pass perpendicularly through the transparentfilm 341*. Infurtherence of thispurpose, the beveled edge 79 of FIG. 3 is providedwith a mirror deposit 81 of silver or the like to provide a reflectivebacking surface for the edge 79.

Referring now to FIG. 4 of the drawings, a modified forin 'ofphotographic means 26 is illustrated therein.

The photographic means 26 likewise is adapted for when irradiated withalpha particles from a suitably radioactive source, for example,polonium or radium. In the case' of poloniu'rn', only a very smallamount of radioactive isotope is required and this may be disposedadjacent the phosphorescentlayer $4 in the form of a very thin-layer 86sandwichedbetween the phosphorescent material '84 and thesupporting'member' 82. Alternatively; the layered can be omitted and theradioactive material thereof can be mixed'uniformly with the phosphormaterial cornprisin g the layer 84.

The supporting member or sheet '82 desirablyis fabri cated from anopaque, flexible, desirably reflective materiaL-forexample, arelativelythin, metallized sheet of Lucite,in order'to prevent loss oflight from the reverse side'of the-light'source 83. Similarly, the-edges88 and 90 of the light sourcefifi can be covered with a suitable opaquebacking material, such as that used in commercial photographicpreparations, to prevent'the emission of light from theseedge surfacesand spurious reflections from adjacent portions of the channel 24,'whichmay be induced thereby.

In thisarrangemen-t it will be apparent that the light source'sfi willbe energizedcontinually throughout the effective life'oftheaforementioned radioisotope, which in the case of polonium is about'60 days. Therefore,

it will be impossible to expose the photographic'film 3t simply byturning the light source 8% on and off, so to speak;

channel or cavity ltand removed from the other end thereof at acontrolled rate in order to provide uniform exposure of the film 3t);Stating the matter differently, the light-sourceBJ-is inserted andwithdrawn at the same speed such that its leading edge fifia-willmovelongitudinally of the film 39 at the-same constant speed when insertingthe light source 8%, as the trailing edge 83b will be moved duringwithdrawal of the light source 8% from the opposite end of the cavity24. However, once the light-source 80'has beeninserted within the cavity24- to a position whereat it is'substantially coextensive with Inthisarrangement of the invention the light Consequently, in thisarrangement of the inven-" tion the light source 8% is inserted atoneend of the the'film an, as illustrated in FIG. 3, the light sourcecan be held in this stationary position for as long a time as isrequired for proper esposure of the film 30.

In furtherance of this purpose, a pair of brackets 92 and 94 are securedat spaced locations to the trailing edge 88b of the source 80. Asuitable pair of handles or other driving meansfid and 98 are rigidlysecured to the brackets 92 and 4 respectively for moving the lightsource 8% during insertion and withdrawal thereof relative to thechannel 24. The handles 96 and 98 can:

be operated manually, if desired, and are of sutficient length to enablean operatorto push the light source 80' into one end of the channel 24and out of the opposite" endthereof. Alternatively, the light source 8hcan-be moved by any suitable'well-known device (not shown) arranged toimpart linear movement to the handles or" driving means 96 and 9S. Inthe latter case, the light source flit can be moved by theaforementioned linear" motiondevice at a suificiently slow rateso thatthe film f 30 is exposed while the light source 80 is being inserted atone end of the channel and withdrawn for the other end thereof ina'continuous operation. In one arrange ment of the invention, whereinthe light'source 80 is moved continuously and a C(lS-polonium screen wasemployed, a speed of approximately two inches per minute has been foundto provide sufficient exposure of the film 3d.

Referring now to FIG. 5 of the drawings, another form of photographicmeans26" is illustrated therein for use in conjunction with the tubularmember 22. The

photographic means 26"likewise includes the photo graphic film 35? whichis inserted into the cavity 24 in the manner described heretofore. Thephotographic; means 26"comprises in addition a light source 1% which asin the case of previous forms of the invention,

is adapted for insertion with the film 3t into'a relativelynarrowchannel 24. In this arrangementthe light source 1% is anelectroluminescentpanel of known design, such as that described incopending applications of Charles' W. Lewis, Electroluminescent LampStructure, filed May 6, 1957, Serial No; 657,356 and'Electrical Apparatus and Solid Dielectric Therefor, filed March 14,

signed to the present assignee'.

source 100" is desired, the'dielectric material 102cm be'tabricated from'aclear plastic'dielectr ic material such as Lucite. The electrodes 194and 106 can be evaporated upon or otherwise deposited as a very thinfilm upon the'dielectric layer 1% electrode coating Hi4 to the film 30with the result that the film 3% is exposed in much the s'ame manner asthat described heretofore in connection with'FlG. 1 of the drawings.Embedded within thedielectric material 102' is an electroluminescentphosphor material such as that described in the aforesaid copendingapplications and' which'is dispersed coextensively with the film 30.

When an alternating potential is applied to the electrode layers'lltl land 1% from a suitable source 108, the fluctuatrons of the electrostaticfield developed between the electrodes til /and 1% causes the glow. Thephor is determined by the voltage applied across the electrodes 11634and 166, while the color or frequency of the embedded phosphor toemitted ligrt is dependent upon the frequency of the alternatingpotential applied thereto. Accordingly, the voltage output of thealternator N3 is adjusted by potenti ometer lit and the frequency of theapplied potential is controlled by suitably adjusting the speed of thedriving motor 112 for the alternator Ill-3 such that'the brightness andcolor of the emitted light matches'the sensitivity of i such that lightdeveloped by the electroluminescent panel can pass through thebrightness of the light emitted fromthe phosone of the commerciallyavailable photographic films described below. Inasmuch as the entiresurface 114 of the electroluminescent panel ill-ll will radiate lightuniformly to the film'3ll, and as the light emitted therefrom can beturned on and off simply by actuation of the switch 116, thephotographic film 3th and the light source Mill can be inserted as aunit into the channel 2 following which the panel ltltl can be energizedfor a time sufiicient to expose the photographic film Ell in the mannerdescribed heretofore in connection with FIGS. 1 and 2 of the drawings.In furtherance of this purpose, the edges of the film 50 and the panelIdll can be bound together by the opaque covering 11% describedhereinafter in connection with FIG. 6 of the drawings to prevent, inaddition, the emission of light from these edges. The conservation oflight can be improved still further by providing a relatively heavyelectrodal film 1% on the outward surface of the panel tea to preventemission of light from the surface and to serve as a reflector to directthe light toward the film 3d.

Another exemplary form of the invention is illustrated in FIG. 6 of thedrawings. In the latter arrangement, the photographic means 26',including the film 3d and a light source denoted generally by thereference character 1239, is inserted as a unit into the channel 24 ofthe tubular member 22. As described heretofore, the film 38 comprises aphotographic emulsion 32 and a transparent backing sheet or member 34,with the photographic emulsion being disposed adjacent the interiorsurface 26 which is being photographed. The film 39 is placed upon aphosphorescent screen comprising the light source 12% and including alayer of phosphorescent material 122 such as zinc sulfide orzinc-cadmium sulfide in a suitable support 124. In FIG. 6 the thicknessof these layers has been somewhat exaggerated, and it is to beunderstood that the photographic means 26' can be made relatively thinfor use in narrow channels and for imparting flexibility theretoin theevent that a non-planar surface is being photographed.

in accordance with the form of the invention exemplifled in FIG. 6, thephosphorescent layer I122 is adapted to be energized by X-rays 126emitted from a known type of cathode ray tube 12%. In this application,assuming that that portion 130 of the tubular element 2th which isdisposed between the phosphorescent or X-ray screen 120 is in the orderof two inches in thickness, soft X-rays, that is to say, X-rays ofcomparatively small penetrating power, can be employed. In thisarrangement the X- rays were produced by the application of a potentialof 125 kilovolts at milliamperes to the cathode ray tube 128.

The exposure time for the film 39 can be controlled readily simply byenergizing and deenergizing the X-ray tube 1'28. This follows from thefact that the X-ray phosphors noted heretofore are standard,short-persistence X-ray screen materials. When using these phosphors,any orthochromatic or panchromatic commercially available film can beused with a yellow-green phosphor such as zinc sulphide. An example ofthese latter-mentioned films is Microfil which is made with atransparent base by the Eastman Kodak Company, Rochester, New York, andPhotolith, also having a clear base made by E. I. Du Pont de Nemours andCompany, Wilmington, Delaware. Any commercially available blue-sensitivefilm provided with a transparent base likewise can be utilized if a bluephosphor is employed for the X-ray screenlZZ.

The foregoing considerations as to color of film and light sourcesapplies equally to the embodiments of the invention illustrated in FIGS.1 to 4 of the drawings.

1 Referring now to FIG. 7 of the drawings, the photographic meansdisclosed by the invention is depicted thcrein as adapted for use withina cylindrical channel such as a bore 132 of a rifle or gun barrel 134.In this arrangement of the invention. a photographic film 136 is shapedinto a cylinder which closely conforms to the inner surface or here 132of the barrel 134. The film 3.36 comprises a transparent cylindricalsupporting membe 138 fabricated desirably from a clear plastic such asLucite and a photographic emulsion Mil deposited uniformly over theexternal surface of the supporting cylinder 11%. Inserted within thecylindrical film support 138 is a cylindrical light source 14 2.

One form of the light source 142 includes a supporting rod 144 which canbe fabricated desirably from a plastic or glass material. Covering theentire outer surface of the rod 143-4 is a coating of a suitablephosphor material id. The individual particles of the phosphor layer 146desirably may be partially or completely embedded in the surface of thesupporting rod 144 if formed from a glass or plastic to improve thehandling characteristics of the light source 142. The phosphorescentcoating 146 can be energized, for example, by means of X-rays in themanner described in connection with FIG. 5 or by means of a radioactivematerial such as described in connection with PEG. 3 of the drawings.

Alternatively, as shown in FIG. 8, the light source 142 7 can bereplaced by a rod 148 of light-conducting material such as Lucite orPlexiglas. In the latter case a suitable light source 15% is securedadjacent an end of the rod 14? and a light-di'lfusional band 152 isimparted to the surface of the light-conductive rod 143 adjacent theother end thereof. This latter-mentioned arrangement of the inventionthen will operate in much the same manner as that described inconnection with FlG. 1 of the drawings, with the light-conductive rod143 being moved either manually or by driving means similar to thatillustrated in FIG. 1.

From the foregoing it will be apparent that a novel and efficicnt meanshas been disclosed herein for photographing areas of limitedaccessibility, particularly the inner surfaces of flat or round tubularmembers. It will be obvious that such uses can be extended readily toapplications involving the photographing of the interiors of pipes andother conduits or the interiors of reactional vessels employed forvarious chemical processes or the like inasmuch as the film 3tl-and thevarious light sources utilized therefor are readily flexible ordeformable to permit the film 30 or 156 to conform to the contour of thesurface being photographed.

The foregoing illustrative and descriptive materials have been employedmerely for purposes of exemplifying the invention and are not to beinterpreted as limitative thereof. Therefore, numerous additionalembodiments or forms of the invention will occur to those skilled in theart without departing from the spirit and scope of the invention.Moreover, it is to be understood that certain features of the inventioncan be employed without a corresponding use of other features thereof.

Accordingly, what is claimed as new is:

1. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film adapted tobe placed adjacent one side of said surface being photographed, alight-conductive'sheet member mounted adjacent the other side of saidfilm and substantially coextending therewith, a light source mountedadjacent an end of said light-conductive member, light-deflecting meansdisposed adjacent the opposite end of said light-conductive member fordirecting light from said member to said film, and means for moving saidlight-conductive member and said ligh -defleeting means to cause saidlight-deflecting means to traverse said film so that light passesthrough said film and is reflected at least partially from said surfaceto expose further said film.

2. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film having oneside thereof positioned adjacent said surface, a light-conductive sheetmember mounted adjacent the other side of said film, a light sourcemounted adjacent one edge of said sheet memlight conducted through saidsheet member and issuing from said last-mentionededge toward saidphotographic film so that light. passes through said film and isreflected at least partially from said surface to expose further saidfilm,and means for moving said sheetmemher to cause saidedge to traversesaid photographic film.

3. In combination, a member having a reflective surface to bephotographed, at substantially transparent photographic'filmhavingoneside thereofdisposed adjacent said surface, a light-conductive sheetmember mounted adjacent the other side of said film and coextendingtherewith, a light source mounted adjacent one end of said sheet member,the opposite edge of said sheet member being beveled outwardly from saidfilm, light reflective material deposited on said outwardly beveled edgeto reflect light being conducted through said sheet member toward andthrough said photographic film, and means for moving said sheet memberto cause said light reflective material to traverse said film.

4. Means for photographing the entire inner reflective surface of atubular member, said means comprising a substantially transparenttubular photographic film having substantially the same contour as thatof said tubular internal surface so that said photographic film can beinserted Within said tubular member and disposed adjacent the internalsurface thereof, a light-conductive member inserted within said tubularfilm and conforming generally to the inner periphery thereof, saidlightconductive member coextending with the length of said film, a lightsource disposed adjacent one end of said light-conductive member, andlight-directing means disposed at the other end of said member fordirecting light being conducted through said member toward the innercircumference of said tubular film so that li ht passes through saidfilm and is reflected at least partially from said surface to exposefurther said film, and means for moving said member and saidlight-directing means to cause said light-directing means to traversethe interior of said tubular film.

5. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film having oneside thereof positioned adjacent said surface, a phosphorescent screenmounted adjacent the opposite side of said film and substantiallycoextending therewith, and means for energizing said screen so thatlight passes through said film and is re flected at least partially fromsaid surface to expose further said film.

6. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film having oneside thereof positioned adjacent said surface, a light source includinga supporting member mounted adjacent the opposite side of said film andcoextending therewith, a layer of phosphorescent material depositeduniformly on said supporting member and coextending therewith, and meansfor energizing said phosphorescent material so that light passes throughsaid film and is reflected at least partially from said surface toexpose further said film, said means including a quantity of radioactiveisotope disposed uniformly adjacent said phosphorescent layer.

7. In combination, a member having a reflective surface to bephotographed, at substantially transparent photographic film having oneside thereof positioned adjacent said surface, a light source includinga supporting member mounted adjacent the opposite side of said film andsubstantially coextending therewith, a layer of phosphorescent materialdeposited uniformly on at least a portion of said supporting member,means for energizing said phosphorescent material so that light passesthrough said film and is reflected at least partially from said surfaceto expose further said film, said means including a quantity ofradioactive isotope disposed uniformly adjacent 'said pho's'phor layer,and meansfor movingsaidlight souree relative to saidphotographic film;

8. In combination, a member having a reflective surface-to bephotographed, a substantially transparent photographicfilm having oneside thereof positioned adjacent-saidsurface, a light source includingasupport ing member'mounted'adjacent the opposite side of said filmandcoextending therewith,"a layer of phosphorescent material'dep'ositeduniformly on said supporting member andcoextending'therewith, means" forenergizing said phosphorescentmaterial, said-means including an X-raytube spacedly disposed from said light source and arranged to irradiatesaid source with X-rays to energize said source so that light passesthrough said film and is reflected at least partially from said surfaceto expose further said film.

9. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film having oneside thereof positioned adjacent said surface, an electroluminescentpanel mounted adjacent the other side of said film and coextendingsubstantially therewith, said panel having electrodal coatings depositedrespectively on opposed surfaces of said panel, the coating facing saidfilm being relatively thinner to permit the passage of light from saidpanel to said film and the coating disposed on the other side of saidpanel being relatively thicker to prevent the loss of light and toreflect light from said panel to said film so that light passes throughsaid film and is reflected at least partially from said surface toexpose further said film, and circuit means for coupling said coatingsto a source of alternating potential.

10. Means for photographing the interior reflective surface of a tubularconduit comprising a transparent tubular photographic film memberadapted for insertion within said conduit and conforming substantiallyto the inner contour of said conduit, a supporting rod inserted withinsaid tubular film and conforming substantially to the inner peripherythereof, said supporting rod having a layer of phosphor materialdisposed uniformly over its outer surface, and means for energizing saidphosphor material so that light passes through said film and isreflected at least partially from said surface to expose further saidfilm.

11. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film having oneside thereof disposed adjacent said surface, a light source disposed onthe other side of said film, and means for conducting light from saidsource to all portions of said other side of said film so that lightpasses through said film and is reflected at least partially from saidsurface to expose further said film.

12. In combination, a member having a reflective surface to bephotographed, a sheet of substantially transparent supporting material,a layer of substantially transparent photographic emulsion disposed onone side of said supporting sheet, said one side being disposed adjacentsaid surface, and an area light source, said source coextending withsaid emulsion and being mounted adjacent the other side of said sheet sothat light passes through said film and is reflected at least partiallyfrom said surface to expose further said film.

13. In combination, a member having a reflective surface to bephotographed, a substantially transparent photographic film, one side ofwhich being juxtaposed to said surface, a light source movably mountedadjacent the other side of said film, and means for moving said sourceto cause said source to scan all portions of said other side so thatlight passes through said film and is reflected at least partially fromsaid surface to expose further said film.

14. Apparatus for photographing a reflective surface of a member, saidapparatus comprising illuminating means disposed to illuminate saidsurface, and a lighttransmitting photographic film positioned betweensaid illuminating means and said surface so' that said light passesthrough said film to said surface and is reflected from said surfacetoward said film, said film being disposed to be substantiallycoextensive with said surface;

15. Apparatus for photographing a reflective surface of a member, saidapparatus comprising means illuminating at least a portion of saidsurface, a light-transmitting photographic film positioned between saidilluminating means and said surface so that light from said illuminatingmeans passes through said film to said surface portion and is reflectedfrom said surface toward said film,

12 said film being disposed to be substantiallycoextensive with saidsurface portion.

References Cited in the file of this patent UNITED STATES PATENTS2,371,843 Powers Mar. 20, 1945 2,494,740 Boucher Jan. 17, 1950 2,523,306Kaiser et a1. Sept. 16, 1950 2,689,306 Land Sept. 14, 1954 2,754,427Berry July 10, 1956 2,796,526 Lusebrink June 18, 1957

1. IN COMBINATION, A MEMBER HAVING A REFLECTIVE SURFACE TO BEPHOTOGRAPHED, A SUBSTANTIALLY TRANSPARENT PHOTOGRAPHIC FILM ADAPTED TOBE PLACED ADJACENT ONE SIDE OF SAID SURFACE BEING PHOTOGRAPHED, ALIGHT-CONDUCTIVE SHEET MEMBER MOUNTED ADJACENT THE OTHER SIDE OF SAIDFILM AND SUBSTANTIALLY COEXTENDING THEREWITH, A LIGHT SOURCE MOUNTEDADJACENT AN END OF SAID LIGHT-CONDUCTIVE MEMBER, LIGHT-DEFLECTING MEANSDISPOSED ADJACENT THE OPPOSITE END OF SAID LIGHT-CONDUCTIVE MEMBER FORDIRECTING LIGHT FROM SAID MEMBER TO SAID FILM, AND MEANS FOR MOVING SAIDLIGHT-CONDUCTIVE MEMBER AND SAID LIGHT-DEFLECTING MEANS TO CAUSE SAIDLIGHT-DEFLECTING MEANS TO TRAVERSE SAID FILM SO THAT LIGHT PASSESTHROUGH SAID FILM AND IS REFLECTED AT LEAST PARTIALLY FROM SAID SURFACETO EXPOSE FURTHER SAID FILM.